There are two major approaches to buying and selling stock - technical and fundamental. As an investor I have a bias for fundamentals, but when you realize the other half of the world is trading technically, it's important to understand that side no matter what your approach.
This is the most concise summary of technical trading I have ever seen. It will get you from zero to sixty faster than any thing else out there. Even if you just want to understand how the other half lives.
JumpStart Your Trading